Find all solutions of the equation in the interval [tex]$[0, 2\pi)$[/tex].

[tex]\[ \cot \theta + \sqrt{3} = 0 \][/tex]

Write your answer in radians in terms of [tex]$\pi$[/tex]. If there is more than one solution, separate them with commas.

[tex]\[ \theta = \][/tex]
[tex]\[ \square \][/tex]



Answer :

To find all solutions to the equation [tex]\(\cot \theta + \sqrt{3} = 0\)[/tex] within the interval [tex]\([0, 2\pi)\)[/tex], we can follow these steps:

1. Rewrite the equation:
[tex]\[ \cot \theta + \sqrt{3} = 0 \][/tex]
This implies:
[tex]\[ \cot \theta = -\sqrt{3} \][/tex]

2. Express cotangent in terms of tangent:
Recall that [tex]\(\cot \theta = \frac{1}{\tan \theta}\)[/tex]. So, we have:
[tex]\[ \frac{1}{\tan \theta} = -\sqrt{3} \][/tex]
Taking the reciprocal of both sides, we get:
[tex]\[ \tan \theta = -\frac{1}{\sqrt{3}} \][/tex]
We can simplify [tex]\(\tan \theta\)[/tex] further as:
[tex]\[ \tan \theta = -\frac{\sqrt{3}}{3} \][/tex]

3. Determine the reference angle:
We know that [tex]\(\tan \theta = \frac{\sqrt{3}}{3}\)[/tex] for [tex]\(\theta = \frac{\pi}{6}\)[/tex]. Therefore, for [tex]\(\tan \theta = -\frac{\sqrt{3}}{3}\)[/tex], the reference angle is still [tex]\(\frac{\pi}{6}\)[/tex], but the tangent function takes negative values in the second and fourth quadrants.

4. Find the solutions in the specified interval:
- Second Quadrant:
[tex]\[ \theta = \pi - \frac{\pi}{6} = \frac{5\pi}{6} \][/tex]
- Fourth Quadrant:
[tex]\[ \theta = 2\pi - \frac{\pi}{6} = \frac{12\pi}{6} - \frac{1\pi}{6} = \frac{11\pi}{6} \][/tex]

Thus, the solutions to the equation [tex]\(\cot \theta + \sqrt{3} = 0\)[/tex] in the interval [tex]\([0, 2\pi)\)[/tex] are:

[tex]\[ \theta = \frac{5\pi}{6}, \frac{11\pi}{6} \][/tex]

In decimal form, these are approximately [tex]\(2.6179938779914944\)[/tex] and [tex]\(5.759586531581287\)[/tex], respectively, which confirms our earlier findings.

So, the final answer is:
[tex]\[ \theta = \frac{5\pi}{6}, \frac{11\pi}{6} \][/tex]